1. Field of the Invention
The invention relates to local area networks and particularly to wireless local area network having distributed control and supporting roaming of mobile units in terms of their contact with mobile access points.
2. Description of the Related Art
The future of the Internet is increasingly wireless, and includes devices that go beyond today's personal computers. These include personal digital assistants (PDAs), and browser-equipped mobile telephones. There are two competing approaches to providing the power of the Internet to these wireless devices. The first of these approaches advanced by the telecommunications industry is called “third generation” (3G) mobile networks. Defined by the International Telecommunications Union (ITU) standards body, 3G provides a global framework for high-speed, high-quality, integrated, mobile digital data and voice communications. Carriers have already paid tens of billions of dollars for licenses to the frequencies reserved for 3G services, and these fees are unlikely to fall far for future licensees. Such figures mean that 3G licenses will be beyond the reach of small, innovative and emerging carriers and service providers. Not only must the 3G carriers recoup their multi-billion-dollar license investments, but they must face additional technological challenges including: limited spectrum, and the need for additional infrastructure investment for many smaller “cells” in the carrier network to support high-speed data traffic.
The second approach relies on unlicensed portions of the radio frequency spectrum. These include 5 GHz alternatives such as HyperLAN/2 and 802.11a industry standards, as well as current 2.4 GHz technologies such as Bluetooth® Telefonaktiebolaget LM Ericsson, Sweden and 802.11b. These standards are specifically designed to allow cable-free connections among small, often handheld, low-power devices. These technologies operate at radio frequencies that are not bound by the regulatory and commercial structures. This parallels the open, accessible and entrepreneurial nature of the Internet itself, significantly lowering market entry costs and creating numerous opportunities for mobile Internet services providers.
What is needed are more flexible ways of coupling wireless devices to the Internet.